Electromagnetic Induction Physics - Electromagnetic Induction

................. gave the principle of Electromagnetic Induction.

A conducting square loop of side l and resistance R moves in its plane with a uniform velocity u perpendicular to one of its sides. A uniform and constant magnetic field B exists along the perpendicular to the plane of the loop as shown in figure. The current induced in the loop is:

The self-inductance of a long solenoid carrying current is independent of:

The current I in an induction coil varies with time t according to the graph shown in the figure. Which of the following graphs shows the induced emf (ε)in the coil with time.

Two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b ), (c) and (d) as given below.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and Rare true but R is NOT the correct explanation of A.
3. A is true but R is false.
4. A is false and R is also false.

Assertion (A): Inductance coil are made of copper.
Reason (R): Induced current is more in wire having less resistance.

Two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b ), (c) and (d) as given below.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and Rare true but R is NOT the correct explanation of A.
3. A is true but R is false.
4. A is false and R is also false.

Assertion (A): When number of turns in a coil doubled, coefficient of self inductance of the coil becomes four times.
Reason (R): Coefficient of self inductance is proportional to the square of number of turns.

Two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b ), (c) and (d) as given below.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and Rare true but R is NOT the correct explanation of A.
3. A is true but R is false.
4. A is false and R is also false.

Assertion (A): An artificial satellite with a metal surface is moving above the earth in a circular orbit. A current will be induced in satellite if the plane of the orbit is inclined to the plane of the equator.
Reason (R): The current will be induced only when the speed of satellite is more than 8km/ sec.

Two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b ), (c) and (d) as given below.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and Rare true but R is NOT the correct explanation of A.
3. A is true but R is false.
4. A is false and R is also false.

Assertion (A): An induced current is developed when the number of magnetic lines of force associated with conductor is changed.
Reason (R): An induced current develop in a conductor moved in a direction parallel to the magnetic field.

Two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b ), (c) and (d) as given below.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and Rare true but R is NOT the correct explanation of A.
3. A is true but R is false.
4. A is false and R is also false.

Assertion (A): Changing magnetic flux can produce induced e.m.f.
Reason (R): Faraday established induced e.m.f. experimentally.

A long straight current carrying wire passes normally through the centre of circular loop. If the current through the wire increases, will there be an induced emf in the loop? Justify.

What is the direction of induced currents in metal rings 1 and 2 when current I in the wire is increasing steadily?

A conducting loop is held below a current carrying wire PQ as shown. Predict the direction of the induced current in the loop when the current in the wire is constantly increasing.

Consider Experiment 6.2. (a) What would you do to obtain a large deflection of the galvanometer? (b) How would you demonstrate the presence of an induced current in the absence of a galvanometer?

State the underlying principle of a transformer.How is the large scale transmission of electric energy over long distances done with the use of transformers?

Sunita and her friends visited an exhibition. The policeman asked them to pass through a metal detector. Sunita’s friends were initially scared of it. Sunita, however, explained to them the purpose and working of the metal detector.
Answer the following questions:

1. On what principle does a metal detector work?
2. Why does the detector emit sound when a person carrying any metallic object walks through it?
3. State any two qualities which Sunita displayed while explaining the purpose of walking through the detector.

A conducting loop is held above a current carrying wire ‘PQ’ as shown in the figure. Depict the direction of the current induced in the loop when the current in the wire PQ is constantly increasing.

Ram is a  student of class X in a village school. His uncle gifted him a bicycle with a dynamo fitted in it. He was very excited to get it. While cycling during night, he could light the bulb and see the objects on the road. He however, did not know this device works. He asked this question to his teacher. the teacher considered it an opportunity to explain the working to the whole class.
Answer the following question:

1. State the principle and working of a dynamo.
2. Write two values each displayed by Ram and his school teacher.

A metallic loop is placed in a nonuniform magnetic field. Will an emf be induced in the loop?

Predict the direction of induced current in the situations described by the following Figs. (a) to (f).

1.  

2.  

3.  

4.  

5.  

6.  

The ____________ motion between the magnet and the coil is responsible for generation (induction) of electric current in the coil.